Green tea extract

ABSTRACT

A process for selectively removing caffeine from a caffeine-containing catechin composition, which includes dissolving the caffeine-containing catechin composition in a 9/1 to 1/9 by weight mixed solution of an organic solvent and water, and then bringing the resultant solution into contact with activated carbon alone or with activated carbon and also acid clay or activated clay; and a packaged beverage containing such a decaffeinated composition.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. Ser. No. 12/971,555,filed on Dec. 17, 2010 now U.S. Pat. No. 8,574,655, which is adivisional of U.S. Ser. No. 10/532,727, filed on Apr. 27, 2005 now U.S.Pat. No. 7,883,734, which is a National Stage (371) of PCT/JP03/13700,filed on Oct. 27, 2003, and claims priority to JP 2002-313080, filed onOct. 28, 2002, JP 2002-313081, filed on Oct. 28, 2002, JP 2002-339735,filed on Nov. 22, 2002, JP 2002-348796, filed on Nov. 29, 2002, JP2002-348791, filed on Nov. 29, 2002, and JP 2003-086895, filed on Mar.27, 2003.

FIELD OF THE INVENTION

This invention relates to a process for selectively removing caffeinefrom a caffeine-containing catechin composition, and also to a packagedbeverage containing a composition obtained by the process.

BACKGROUND OF THE INVENTION

Catechins are known to have inter alia a suppressing effect on anincrease in cholesterol level and an inhibitory effect on α-amylaseactivity (for example, JP-A-60-156614 and JP-A-03-133928). To have suchphysiological effects of catechins developed, it is necessary for anadult to drink 4 to 5 cups of tea in a day. Accordingly, there is anoutstanding desire for technology that permits the addition of catechinsat high concentration in beverages to facilitate the ingestion of alarge amount of catechins.

In tea leaves, however, caffeine components are also contained generallyat from 2 to 4% although catechins are contained as much as about 15%.As caffeine exhibits a central nervous system stimulant effect, it isused for the suppression of sleepiness. On the other hand, its excessiveingestion is said to become a cause of induction of adverse effects suchas nervosity, nausea and hyposomnia. Thus investigations have been madeabout processes that can selectively remove only caffeine fromcaffeine-containing compositions.

As decaffeination processes of coffee, for example, there have beenproposed a process that coffee is brought into contact with a caffeineadsorbent such as activated carbon under from 150 to 250 atm(JP-A-53-18772) and a process that caffeine is selectively removed bybringing a caffeine-containing, aqueous solution into contact withactivated clay or acid clay (JP-A-06-142405).

However, the former relates to a supercritical extraction technique, sothat it requires substantial investment on process equipment and lacksreadiness in its practice on an industrial level. This process alsoinvolves a problem in that it achieves not only selective removal ofonly caffeine but also results in a modification to the composition ofcatechins as effective ingredients. The latter process, on the otherhand, is accompanied by a problem in that the hue may deteriorate insome instances, although caffeine can be selectively removed by simplyusing activated clay or acid clay.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a process forselectively removing caffeine from a caffeine-containing catechincomposition without substantially changing the composition of catechinsand moreover, without deteriorating the hue. Another object of thepresent invention is to provide a packaged beverage containing adecaffeinated, catechin-containing composition obtained as describedabove.

The present inventors have found that caffeine contained in a catechincomposition can be selectively removed without substantially changingthe composition of catechins and also deteriorating the hue by bringingthe catechin composition, in a state dissolved in a mixed water/organicsolvent solution of a specific ratio, into contact with activated carbonalone or with activated carbon and acid clay or activated clay. Theyhave also found that a tea extract obtained as described above is goodin hue and stability while containing catechins and is useful as abeverage or as a raw material for beverages.

Therefore, the present invention provides a process for selectivelyremoving caffeine from a caffeine-containing catechin composition, whichcomprises dissolving the caffeine-containing catechin composition in a9/1 to 1/9 by weight mixed solution of an organic solvent and water, andthen bringing the resultant solution into contact with activated carbon.

The present invention also provides a process for selectively removingcaffeine from a caffeine-containing catechin composition, whichcomprises dissolving the caffeine-containing catechin composition in a9/1 to 1/9 by weight mixed solution of an organic solvent and water, andthen bringing the resultant solution into contact with activated carbonand acid clay or activated clay.

The present invention also provides a process for producing a green teaextract, which comprises dissolving a caffeine-containing catechincomposition in a 9/1 to 1/9 by weight mixed solution of an organicsolvent and water, and then bringing the resultant solution into contactwith activated carbon to selectively remove caffeine.

The present invention further provides a process for producing a greentea extract, which comprises dissolving a caffeine-containing catechincomposition in a 9/1 to 1/9 by weight mixed solution of an organicsolvent and water, and then bringing the resultant solution into contactwith activated carbon and acid clay or activated clay to selectivelyremove caffeine.

The present invention still further provides a caffeine-containing teaextract, wherein:

(a) a content of gallates in non-polymer catechins is from 45 to 60 wt%,

(b) a weight ratio of the non-polymer catechins to caffeine is from 8 to40,

(c) a weight ratio of the non-polymer catechins to (sucrose+glucose) isfrom 2 to 15, and

(d) dietary fibers amount to 0.5 wt % or less of a solid content.

The present invention yet further provides a packaged beveragecomprising a green tea extract obtained by one of the above-describedprocesses.

DETAILED DESCRIPTION OF THE INVENTION

A caffeine-containing catechin composition used in the present inventioncontains one or more non-polymer catechins. The term “non-polymercatechins” as used herein is a generic term, which collectivelyencompasses non-epicatechins such as catechin, gallocatechin,catechingallate and gallocatechingallate, and epicatechins such asepicatechin, epigallocatechin, epicatechingallate andepigallocatechingallate.

As caffeine-containing catechin compositions containing non-polymercatechins, extracts obtained from tea leaves such as green tea, blacktea and oolong tea can be mentioned. In addition, mixtures of caffeinederived from caffeine-containing plants such as coffee with tea extractsare also usable.

Tea leaves for use in the present invention include, tea leaves preparedfrom tea leaves of the Genus Camellia, for example, C. sinensis, C.assamica and the Yabukita variety, or their hybrids. Such prepared tealeaves include green teas such as sencha (middle-grade green tea),bancha (coarse green tea), gyokuro (shaded green tea), tencha (powderedtea) and kamairicha (roasted tea).

The extraction of a caffeine-containing catechin composition from tealeaves can be conducted by a method such as stirring extraction. Anorganic acid or organic acid salt, such as sodium ascorbate, can beadded beforehand to water upon extraction. It is also possible to makecombined use of boiling deaeration or an extraction method which isconducted while bubbling an inert gas such as nitrogen gas to eliminatedissolved oxygen, that is, under a so-called non-oxidizing atmosphere.

Instead of extracting from tea leaves, it is also possible to use aconcentrate of a tea extract or a purified product of a concentrate of atea extract in a form dissolved in or diluted with water. It is alsopossible to use an extract from tea leaves in combination with aconcentrate of a tea extract or a purified product of a concentrate of atea extract.

The term “the concentrate of a tea extract” as used herein means oneobtained by concentrating an extract of tea leaves in hot water or awater-soluble organic solvent, and includes, for example, those preparedby the processes disclosed in JP-A-59-219384, JP-A-04-20589,JP-A-05-260907, JP-A-05-306279 and the like.

As the concentrate of a tea extract, it is possible to use, specificallya commercially-available crude catechin preparation such as “POLYPHENON”(product of Tokyo Food Techno Co., Ltd.), “TEAFURAN” (product of ITO EN,LTD.) or “SUNPHENON” (product of Taiyo Kagaku Co., Ltd.).

As the caffeine-containing catechin composition used as a raw material,it is preferred to use a green tea extract containing from 25 to 90 wt%, more preferably from 25 to 70 wt %, even more preferably from 25 to40 wt % of non-polymer catechins in terms of solid content, becausetaste components other than the non-polymer catechins still remain. Theterm “solid content” as used herein means the weight of acaffeine-containing catechin composition as determined when thecaffeine-containing catechin composition is dried and solidified.

As the purified product of the concentrate of the tea extract, onepurified by one of the following processes (1) to (3) is preferred.

(1) A process for purifying a solid concentrate of a tea extract, saidsolid concentrate containing from 25 to 40 wt % of non-polymercatechins, which comprises adding the solid concentrate to a 10/0 to 8/2by weight solvent of an organic solvent and water, adding water to theresultant mixture to adjust a weight ratio of the organic solvent towater to from 9/1 to 5/5, removing undissolved solids, and then,distilling off the solvent.

(2) A process for purifying a solid concentrate of a tea extract, saidsolid concentrate containing from 25 to 40 wt % of non-polymercatechins, which comprises adding the solid concentrate to a 10/0 to 8/2by weight solvent of an organic solvent and water, adding water to theresultant mixture to adjust a weight ratio of the organic solvent towater to a range of from 9/1 to 5/5, removing solids from the resultantsuspension, and then, distilling off the solvent from a remaining liquidphase.

(3) A process for purifying a concentrate of a tea extract, saidconcentrate containing from 25 to 40 wt % of non-polymer catechins,which comprises dissolving the concentrate in a mixed solvent of waterand an organic solvent, adding an organic solvents to the resultantsolution to adjust a weight ratio of the organic solvents to water to arange of from 9/1 to 5/5 such that a precipitate is formed, removingsolids from the resultant suspension, and then distilling off theorganic solvents from a remaining liquid phase.

As the concentrate of the tea extract for use in these purificationprocesses (1) to (3), a commercially-available catechin preparation ispreferred.

A description will firstly be made about the purification processes (1)and (2).

In the purification processes (1) and (2), the solid concentrate of thetea extract is firstly added to and suspended in a 10/0 to 8/2 by weightsolvent of an organic solvent and water.

Organic solvents usable at this time include ethanol, methanol, acetone,ethyl acetate, and the like. Preferred are hydrophilic organic solventssuch as ethanol, methanol and acetone, with ethanol being more preferredin view of the remaining of the organic solvent as the purified productis assumed to be used in foods.

The weight ratio of the organic solvent to water in the solvent to beused is preferably from 10/0 to 8/2 from the viewpoint of thedispersibility of the solid concentrate of the tea extract.

The weight ratio of the concentrate of the tea extract to the solventcan be preferably from 5:95 to 40-60, more preferably from 10:90 to30:70 from the standpoint of the efficiency of extraction of non-polymercatechins.

Water is then added to the suspension. As a consequence, water-solublecomponents contained in the concentrate of the tea extract, such asnon-polymer catechins, are subjected to solid-liquid extraction fromsolid to water. The amount of the water to be added to the suspension issuch an amount as required to adjust the weight ratio of the organicsolvent to water to from 9/1 to 5/5, preferably from 8/2 to 6/4. Anorganic solvent/water ratio higher than 9/1 leads to a reduction in theefficiency of extraction from the concentrate of the tea extract towater upon conducting the solid-liquid extraction, and therefore, is notpreferred. An organic solvent/water ratio lower than 5/5, on the otherhand, results in an insufficient taste-improving effect, and therefore,is not preferred. It is to be noted that water is added further evenwhen the weight ratio of the organic solvent to water in the solventused at the first is from 9/1 to 8/2. By the addition of water,water-soluble components such as non-polymer catechins are subjected tosolid-liquid extraction so that a purified product of a concentrate of atea extract is obtained with good flavor and taste.

As the manner of addition of water, it is preferred to slowly add itdropwise as much as needed over a time of from 10 to 30 minutes or so,and for an improvement in the efficiency of solid-liquid extraction, itis preferred to add it dropwise under stirring. It is still morepreferred to include an aging time of from 10 minutes to 40 minutes orso after the completion of the dropwise addition of water.

Upon adding the mixed solvent, adding water or conducting thesolid-liquid extraction, the temperature can be from 0 to 60° C.,preferably from 10 to 60° C., more preferably from 10 to 40° C. from thestandpoint of convenience for the control of the purification stepconsidering that an organic solvent is used.

Solids are then separated from the suspension, and from the remainingliquid phase, the organic solvent is distilled off to afford a purifiedproduct as desired. As a solid-liquid separation method, a conventionalmethod, for example, centrifugation, filtration or the like can be used.As a distillation method of the organic solvent from the liquid phaseobtained by the separation, reduced-pressure distillation is preferredto avoid a heat load on the purified product as much as possiblealthough any conventional method can be used.

A description will next be made about the purification process (3).

In the purification process (3), the concentrate of the tea extract isfirstly dissolved in water or a mixture of water and an organic solvent.Organic solvents usable at this time include ethanol, methanol, acetone,ethyl acetate, and the like. Preferred are hydrophilic organic solventssuch as ethanol, methanol and acetone, with ethanol being more preferredin view of the remaining of the organic solvent as the purified productis assumed to be used in beverages.

The solvent for use in the dissolution of the concentrate of the teaextract is the mixture of water and the organic solvent. The weightratio of water to the organic solvent can be adjusted between 9/1 and5/5. A ratio smaller than 5/5 leads to a deterioration in the solubilityof the concentrate of the tea extract, and hence, to a reduction in theextraction efficiency of the liquid-liquid extraction.

An organic solvent is then gradually added to the solution of theconcentrate of the tea extract such that a precipitate of insolublecomponents is formed in the solution of the concentrate of the teaextract. As the organic solvent for use in this step, the same organicsolvent as that used in the above is preferred.

It is necessary to add, to the solution of the concentrate of the teaextract, the organic solvent in an amount sufficient to adjust theweight ratio of the organic solvents to water to a range of from 9/1 to5/5, preferably from 8/2 to 6/4 from the standpoint of formation of aprecipitate of insoluble components. An organic solvents/water ratiogreater than 9/1 requires to use the organic solvent in a considerablylarge amount, and therefore, is not preferred economically. An organicsolvents/water ratio smaller than 5/5, on the other hand, leads to adeterioration in the separability of the precipitate by filtration, andtherefore, is not preferred.

As the manner of addition of the organic solvent, it is preferred toslowly add it dropwise as much as needed over a time of from 10 to 30minutes or so, and for an improvement in the efficiency of formation ofinsoluble components, it is preferred to add it dropwise under stirring.It is still more preferred to include an aging time of from 10 minutesto 40 minutes or so after the completion of the dropwise addition ofwater.

Upon forming the precipitate of the insoluble components by the additionof the organic solvent to the solution of the concentrate of the teaextract, no particular limitation is imposed on the temperature.Nonetheless, the temperature can be preferably from 0 to 60° C., morepreferably from 10 to 60° C., even more preferably from 10 to 40° C.from the standpoint of convenience for the control of the purificationstep considering that an organic solvent is used.

Solids are then separated from the suspension, and from the remainingliquid phase, the organic solvents are distilled off to afford apurified product as desired. As a solid-liquid separation method, aconventional method, for example, centrifugation, filtration or the likecan be used. As a distillation method of the organic solvent from theliquid phase obtained by the separation, reduced-pressure distillationis preferred to avoid a heat load on the purified product as much aspossible although any conventional method can be used.

A description will next be made about the process for selectivelyremoving caffeine from the caffeine-containing catechin composition.

Firstly, the caffeine-containing catechin composition is dissolved in a9/1 to 1/9 mixed solution of an organic solvent and water.

Organic solvents usable at this time include ethanol, methanol, acetone,ethyl acetate, and the like. Among these, preferred are hydrophilicorganic solvents such as ethanol, methanol and acetone, with ethanolbeing more preferred in view of the use of the purified product infoods.

In the present invention, it is necessary to adjust the weight ratio ofthe organic solvent to water to a range of from 9/1 to 1/9, preferablyfrom 9/1 to 5/5, more preferably from 8/2 to 6/4. A proportion of theorganic solvent greater than 9/1 leads to a reduction in the efficiencyof extraction of catechins, while a proportion of the organic solventsmaller than 1/9 results in an insufficient taste-improving effect forthe decaffeinated product.

No particular limitation is imposed on the method for dissolving thecaffeine-containing catechin composition in the mixed solution of theorganic solvent and water. The weight ratio of the organic solvent towater can be adjusted to the range of from 9/1 to 1/9 by adding theorganic solvent subsequent to the dissolution of the caffeine-containingcatechin composition in water. As an alternative, the organic solventand water can be brought to a similar ratio by gradually adding watersubsequent to the suspension of the caffeine-containing catechincomposition in the organic solvent. From the standpoint of theefficiency of extraction, however, it is preferred to gradually add theorganic solvent subsequent to the dissolution in water. Upon treatmentof the caffeine-containing catechin composition, catechins are adsorbedon activated carbon or on activated carbon and also acid clay oractivated clay when the treatment is conducted in water alone. Asopposed to the treatment in water alone, the existence of the organicsolvent makes it possible to avoid such phenomenon.

In the present invention, it is preferred to conduct the treatment byadding from 10 to 40 weight parts, especially from 15 to 30 weight partsof the caffeine-containing catechin composition to 100 weight parts ofthe mixed solution of the organic solvent and water, because thecaffeine-containing catechin composition can be treated efficiently.

As to the time needed to add water or the organic solvent, it ispreferred to slowly add it dropwise over a time of from 10 to 30 minutesor so, and for an improvement in the efficiency of extraction ofcatechins, it is preferred to add it dropwise under stirring. It isstill more preferred to include an aging time of from 10 minutes to 120minutes or so after the completion of the dropwise addition of water.

These treatments can be conducted at from 10 to 60° C., preferably from10 to 50° C., more preferably from 10 to 40° C.

No particular limitation is imposed on the activated carbon for use inthe present invention insofar as it is generally used on an industriallevel. Usable examples include commercially-available products such as“ZN-50” (product of Hokuetsu Carbon Industry Co., Ltd.), “KURARAY COALGLC”, “KURARAY COAL PK-D” and “KURARAY COAL PW-D” (products of KurarayChemical K.K.), and “SHIROWASHI AW50”, “SHIROWASHI A”, “SHIROWASHI M”and “SHIROWASHI C” (products of Takeda Pharmaceutical Company Limited).

The pore volume of the activated carbon may be preferably from 0.01 to0.8 mL/g, more preferably from 0.1 to 0.7 mL/g. Concerning the specificsurface area, on the other hand, one having a specific surface area in arange of from 800 to 1,300 m²/g is preferred, within which the range offrom 900 to 1,200 m²/g is more preferred. It is to be noted that thesephysical values are those obtained by the nitrogen adsorption method.

The activated carbon can be added preferably in a proportion of from 0.5to 5 weight parts, more preferably in a proportion of from 0.5 to 3weight parts to 100 weight parts of the mixed solution of the organicsolvent and water. The addition of the activated carbon in anexcessively small proportion leads to a deterioration in the efficiencyof removal of caffeine, while the addition of the activated carbon in anexcessively large proportion leads to an increase in the cake resistancein a filtration step. It is, therefore, not preferred to add theactivated carbon in a proportion outside the above-described range.

Acid clay and activated clay for use in the present invention bothcontain, as general chemical components, SiO₂, Al₂O₃, Fe₂O₃, CaO, MgO,etc., and those having SiO₂/Al₂O₃ ratios of from 3 to 12 are preferred,within which the ranges of from 4 to 9 are more preferred. Alsopreferred are those which have compositions containing from 2 to 5 wt %of Fe₂O₃, from 0 to 1.5 wt % of CaO and from 1 to 7 wt % of MgO.

Activated clay is obtained by treating naturally-occurring acid clay(montmorillonite clay) with a mineral acid such as sulfuric acid, and isa compound having a porous structure of large specific surface area andadsorbability. Further treatment of acid clay with an acid is known tochange its specific surface area such that its decoloring ability isimproved and its physical properties are modified.

The specific surface area of acid clay or activated clay may bepreferably from 50 to 350 m²/g although it varies depending on thedegree or the like of the acid treatment, and its pH (5% suspension) maybe preferably from 2.5 to 8, more preferably from 3.6 to 7. Usableexamples of acid clay include commercially-available products such as“MIZUKA ACE #600” (product of Mizusawa Chemical Industries, Ltd.).

Acid clay or activated clay can be added preferably in a proportion offrom 2.5 to 25 weight parts, more preferably in a proportion of from 2.5to 15 weight parts to 100 weight parts of the mixed solution of theorganic solvent and water. The addition of acid clay or activated clayin an unduly small proportion leads to a deterioration in the efficiencyof removal of caffeine, while the addition of acid clay or activatedclay in an excessively large proportion leads to an increase in the cakeresistance in the filtration step. It is, therefore, not preferred toadd acid clay or activated clay in a proportion outside theabove-described range.

When activated carbon is used in combination with acid clay or activatedclay, the ratio of activated carbon to acid clay or activated clay maypreferably be from 1 to 10 of acid clay or activated clay to 1 activatedcarbon by weight, with activated carbon:acid clay or activated clay=1:1to 1:6 being more preferred. Upon bringing into contact with thecaffeine-containing catechin composition, activated carbon and acid clayor activated clay can be both brought into contact at the same time orcan be individually brought into contact one after another (nolimitation is imposed on their order).

The treatment of the caffeine-containing catechin composition by itscontact with activated carbon or with activated carbon and also acidclay or activated clay can be conducted by any method such as abatchwise treatment method or a continuous treatment method making useof a column. Adopted in general is a method that powdery activatedcarbon or the like is added, the resulting mixture is stirred toselectively adsorb caffeine, and filtration is conducted to obtain adecaffeinated filtrate or a method that caffeine is selectively adsorbedby continuous treatment through a column packed with granular activatedcarbon or the like.

After having been brought into contact with activated carbon or withactivated carbon and also acid clay or activated clay, the solution withthe catechin composition contained therein is subjected to distillationsuch as reduced-pressure distillation to remove the organic solvent formthe system. After the treatment, the catechin composition can be eitherliquid or solid. To prepare its a solid form, the catechin compositioncan be formed into powder by a method such as lyophilization or spraydrying.

After the decaffeination treatment by the present invention, thecatechin composition preferably contains the non-polymer catechins witha composition substantially unchanged from that before the treatment.The yield of the non-polymer catechins in the mixed solution of theorganic solvent and water after the treatment may be preferably 70 wt %or higher, more preferably 80 wt % or higher. Accordingly, the contentof the non-polymer catechins in the composition after the decaffeinationtreatment may preferably be from 80 to 95 wt %, more preferably from 85to 95 wt %, even more preferably from 90 to 95 wt % in terms of solidcontent.

Concerning the non-polymer catechins in the catechin composition afterthe decaffeination treatment by the present invention, the ratio ofgallocatechins, which consist of epigallocatechingallate,gallocatechingallate, epigallocatechin and gallocatechin, tonon-gallocatechins, which consist of epicatechingallate,catechingallate, epicatechin and catechin, can preferably retain thecorresponding ratio in natural green tea leaves. In other words, it ispreferred from the standpoint of also retaining the composition ofnatural green tea leaves in the purified product that the total amountof the above-described four gallocatechins always exceeds the totalamount of the above-described four non-gallocatechins.

As the concentration of caffeine relative to that of the non-polymercatechins in the catechin composition after the decaffeination treatmentby the present invention, the weight ratio (b) of the non-polymercatechins to caffeine may be preferably from 7 to 60, more preferablyfrom 7 to 50, even more preferably from 8 to 40.

In the catechin composition after the decaffeination treatment by thepresent invention, the content (a) of the gallates, which consist ofcatechingallate, epicatechingallate, gallocatechingallate andepigallocatechingallate, in the non-polymer catechins may be preferably45 wt % or greater, more preferably from 45 to 60 wt % from thestandpoint of the effectiveness of physiological effects of thenon-polymer catechins.

The weight ratio (c) of the non-polymer catechins to (sucrose+glucose)in the catechin composition after the decaffeination treatment may bepreferably from 2 to 15, more preferably from 2 to 10, even morepreferably from 2 to 8, even more preferably from 3 to 7. A ratiogreater than 15 involves a problem in the flavor of the tea extract,while a ratio smaller than 2 is not preferred because the saccharidecontent becomes too abundant.

From the standpoint of readiness in the migration of the non-polymercatechins, dietary fibers (d) may amount preferably to 0.5 wt % or less,more preferably to from 0 to 0.3 wt % of the solid content of thecatechin composition after the decaffeination treatment.

The addition of the catechin composition obtained after thedecaffeination treatment makes it possible to obtain a beverage having ahigh non-polymer catechin concentration and a low caffeineconcentration. As the beverage, a packaged beverage is preferred.

The packaged beverage according to the present invention is a beveragewith the above-described specific decaffeinated composition addedtherein. Beverages and the like, to which the specific decaffeinatedcomposition can be added, include green tea, an extracts of tea selectedfrom semi-fermented tea or fermented tea, and non-tea beverages. Amongthese, preferred is a beverage with the decaffeinated composition addedto a tea extract, and preferred is a green tea beverage with thedecaffeinated composition added to an extract of green tea. Illustrativeof the semi-fermented tea is oolong tea, and illustrative of thefermented tea is black tea. Examples of the non-tea beverage includecarbonated beverages as soft drinks, beverages with fruit extract orextracts, juices with vegetable extract or extracts, near waters, sportsdrinks, and diet drinks.

The packaged beverage according to the present invention containsgenerally from 0.092 to 0.5 wt %, preferably from 0.1 to 0.4 wt %, morepreferably from 0.11 to 0.3 wt %, even more preferably from 0.12 to 0.3wt % of the non-polymer catechins, which are non-polymers and are inwater-dissolved forms. When the content of the non-polymer catechinsfalls within the above-described range, a Large amount of thenon-polymer catechins can be ingested with ease without producing strongbitterness, astringency and sharp puckeriness. The concentration of thenon-polymer catechins can be adjusted depending on the amount of thedecaffeinated composition to be added.

The content (a) of gallates—which consist of catechingallate,epicatechin gallate, gallocatechin gallate and epigallocatechingallate—in the non-polymer catechins in the packaged beverage accordingto the present invention may preferably be 45 wt % or greater, morepreferably from 45 to 60 wt % from the standpoint of the effectivenessof the physiological effects of the non-polymer catechins.

As the concentration of caffeine relative to that of the non-polymercatechins in the packaged beverage according to the present invention,the weight ratio (b) of the non-polymer catechins to caffeine may bepreferably from 7 to 60, more preferably from 7 to 50, even morepreferably from 8 to 40.

The weight ratio (c) of the non-polymer catechins to (sucrose+glucose)in the packaged beverage according to the present invention may bepreferably from 2 to 15, more preferably from 2 to 10, even morepreferably from 2 to 8, even more preferably from 3 to 7. A ratiogreater than 15 involves a problem in the flavor of the tea extract,while a ratio smaller than 2 is not preferred because the saccharidecontent of the tea extract is too high.

Dietary fibers (d) may amount to 0.5 wt % or less of the solid contentof the catechin composition in the packaged beverage according to thepresent invention after the decaffeination treatment, and from thestandpoint of readiness in the absorption of the non-polymer catechins,it is preferred to contain no dietary fibers.

It is preferred to add a bitterness suppressor to the packaged beverageaccording to the present invention, because its addition renders thepackaged beverage more palatable. No particular limitation is imposed onthe bitterness suppressor to be used, although cyclodextrins arepreferred. Usable examples of the cyclodextrins include α-, β- andγ-cyclodextrins and branched α-, β- and γ-cyclodextrins. A cyclodextrincan be contained at from 0.01 to 0.5 wt %, preferably at from 0.01 to0.3 wt % in the beverage.

From the standpoint of the chemical stability of the non-polymercatechins, the pH of the beverage may be preferably from 2 to 7, morepreferably from 3 to 7, even more preferably from 5 to 7, all at 25° C.

For the packaged beverage according to the present invention, it ispossible to add, in combination with the ingredients derived from tea,additives—such as antioxidants, flavors, various esters, organic acids,organic acid salts, inorganic acids, inorganic salts, colorants,emulsifiers, preservatives, seasoning agents, sweeteners, sourseasonings, fruit extracts, vegetable extracts, flower honey extracts,pH regulators and quality stabilizers—either singly or in combination asingredients which can be added in light of the formulation.

Examples of the sweeteners include sugar, glucose, fructose, isomerizedsyrup, glycyrrhizin, stevia, aspartame, fructooligosaccharide, andgalactooligosaccharide. Examples of the sour seasonings include, inaddition to fruit juices and the like extracted from natural sources,citric acid, tartaric acid, malic acid, lactic acid, fumaric acid, andphosphoric acid. These sweeteners and sour seasonings may be containedpreferably in an amount of from 0.01 to 0.5 wt %, with from 0.01 to 0.3wt % being more preferred.

Examples of the inorganic acids and inorganic acid salts includephosphoric acid, disodium phosphate, sodium metaphosphate, and sodiumpolyphosphate. These inorganic acids and inorganic acid salts may becontained in an amount of from 0.01 to 0.5 wt %, with from 0.01 to 0.3wt % being preferred, in the beverage.

Similar to general beverages, a container useful for the packagedbeverage according to the present invention can be provided in anordinary form such as a molded container made of polyethyleneterephthalate as a principal component (so-called PET bottle), a metalcan, a paper container combined with metal foils or plastic films, or abottle. The term “packaged beverage” as used herein means a beveragewhich can be drunken without dilution.

The packaged beverage according to the present invention can beproduced, for example, by filling the beverage in a container such as ametal can and, when heat sterilization is feasible, conducting heatsterilization under sterilization conditions as prescribed in the FoodSanitation Act. For those which cannot be subjected to retortsterilization like PET bottles or paper containers, a process is adoptedsuch that the beverage is sterilized beforehand under similarsterilization conditions as those described above, for example, by aplate-type heat exchanger, is cooled to a particular temperature, and isthen filed in a container. Under aseptic conditions, additionalingredients may be added to and filled in a filled container. It is alsopossible to conduct an operation such that subsequent to heatsterilization under acidic conditions, the pH of the beverage isadjusted to return to neutral under aseptic conditions or thatsubsequent to heat sterilization under neutral conditions, the pH of thebeverage is adjusted to return to the acidic side under asepticconditions.

In the present invention, the purified product obtained by any one ofthe purification processes (1) to (3) contains non-polymer catechins athigh concentration and has an improvement in astringency and bitterness,and further, beverages with the purified product added therein have beenfound to be good in flavor and taste. The present invention, therefore,provides the purification processes (1) to (3) and packaged beveragescontaining purified products obtained by any one of the purificationprocesses (1) to (3).

The concentration of non-polymer catechins in each purified productaccording to the present invention can be preferably from 26 to 55 wt %,more preferably from 30 to 55 wt %, even more from 30 to 55 wt %, evenmore preferably from 35 to 55 wt %.

If the concentration of non-polymer catechins in a purified product islower than 25 wt %, the effects of other taste components contained inthe purified product of the green tea extract come to the fore so that ahigh non-polymer catechins beverage with the purified product addedtherein gives a feeling of disagreeable bitterness without anyrefreshing sensation. Therefore, such a low concentration of non-polymercatechins is not preferred. If the concentration of non-polymercatechins in a purified product is higher than 55 wt %, on the otherhand, dainty components other than the non-polymer catechins in thepurified product as a catechin preparation have been excessively removedtogether with oxalic acid. Such a purified product is, therefore, notpreferred as a purified product to be added as a catechin preparation tobeverages.

It is preferred that the ratio of the gallates—which consist ofepigallocatechin gallate, gallocatechin gallate, epigallocatechin andgallocatechin—to the nongallates—which consist of epicatechin gallate,catechingallate, epicatechin and catechin—in the purified productaccording to the present invention retain the same ratio as in naturalgreen tea leaves. From the standpoint of also retaining the catechincomposition of natural green tea leaves in the purified product, it is,therefore, preferred that the total amount of the four types of gallatesbe always greater than the total amount of the four types ofnongallates.

The content of the gallates—which consist of catechingallate,epicatechin gallate, gallocatechin gallate and epigallocatechingallate—in the purified product according to the present invention maypreferably be 45 wt % or greater from the standpoint of theeffectiveness of the physiological effects of the non-polymer catechins.

In each purified product obtained by any one of the purificationprocesses according to the present invention, the content weight ratio[(B)/(A)] of (B) oxalic acid to the non-polymer catechins (A) may bepreferably from 0.002 to 0.035, more preferably from 0.002 to 0.03, evenmore preferably from 0.0025 to 0.03, even more preferably from 0.0025 to0.02. An unduly small content of oxalic acid in a purified product meansexcessive removal of dainty components and the like together with oxalicacid, so that such a purified product is not preferred as a purifiedproduct to be added to beverages. An excessively high content of oxalicacid in a purified product, on the other hand, results in a beverage,which gives a feeling of disagreeable bitterness without any refreshingsensation as felt from the concentrate before the purification.Therefore, such an excessively high content is not preferred.

The concentration of oxalic acid in a purified product according to thepresent invention may be preferably from 0.05 to 1.5 wt %, morepreferably from 0.05 to 1.0 wt %, even more preferably from 0.05 to 0.5wt %, even more preferably from 0.08 to 0.3 wt %. If the concentrationof oxalic acid in the purified product is higher than 1.5 wt %, theoxalic acid component contained in the purified product substantiallyaffects the taste so that a high non-polymer catechins beverage with thepurified product added therein gives a feeling of sharp bitternesswithout any refreshing sensation. Therefore, such a high concentrationof oxalic acid is not preferred. If the concentration of oxalic acid ina purified product is lower than 0.05 wt %, on the other hand, daintycomponents other than the non-polymer catechins in the purified producthave been excessively removed together with oxalic acid. Such a purifiedproduct is, therefore, not preferred as a purified product to be addedto beverages.

The use of a green tea extract in the form of a purified product inwhich the content weight ratio [(A)/(C)] of (A) non-polymer catechins to(C) total polyphenols has been adjusted to 0.83 to 0.96 provides apackaged beverage the color tone of which remains good even afterstorage.

The content weight ratio [(A)/(C)] of (A) the non-polymer catechins to(C) the total polyphenols in the green tea extract can be from 0.83 to0.96, preferably from 0.83 to 0.94, more preferably from 0.84 to 0.93,even more preferably from 0.84 to 0.92. An excessively low ratio ofnon-polymer catechins to total phenols in a green tea extract results inthe abundant inclusion of components other than the non-polymercatechins in a beverage, thereby impairing the stability of the colortone of the beverage during its storage. Therefore, such an excessivelylow ratio is not preferred. An unduly high ratio of non-polymercatechins to total phenols in a green tea extract leads to a change tothe balance of flavor and taste of the beverage. Therefore, such anexcessively high ratio is not preferred either.

The term “total polyphenols” as used herein means ingredientsquantitated by the method that by using ethyl gallate as a standardsolution, their total amount is determined as an amount converted togallic acid by the ferrous tartrate method (referential publication:“Green Tea Polyphenols” (in Japanese), Technology Series for theEffective Utilization of Functional Ingredients for Beverages and Foods,No. 10). In general, non-polymer catechins and their polymers and thelike can be detected by this measurement method.

It is preferred that the ratio of the gallates—which consist ofepigallocatechin gallate, gallocatechin gallate,epigallocatechinandgallocatechin—to the nongallates—which consist ofepicatechin gallate, catechingallate, epicatechin and catechin—in thegreen tea extract retain the same ratio as in natural green tea leaves.Accordingly, the purification should be conducted under such conditionsthat the total amount of the four types of gallates is always greaterthan the total amount of the four types of nongallates.

The content of the gallates—which consist of catechingallate,epicatechin gallate, gallocatechin gallate and epigallocatechingallate—in the green tea extract may preferably be 45 wt % or greaterfrom the standpoint of the effectiveness of the physiological effects ofthe non-polymer catechins.

The concentration of (C) total polyphenols in the green tea extract maybe preferably from 35 to 60 wt %, more preferably from 35 to 55 wt %,even more preferably from 40 to 55 wt %. If the concentration of totalpolyphenols in a green tea extract is higher than 60 wt %, the contentof other taste components contained in the green tea extract is low sothat the green tea extract may be disturbed in the balance of its flavorand taste. If the concentration of total polyphenols in a green teaextract is lower than 35 wt %, on the other hand, the concentration ofnon-polymer catechins as an effective ingredient is low so that thegreen tea extract has to be added in a greater amount to a beverage.

A packaged beverage with the green tea extract added therein can be atea-based beverage or non-tea-based beverage like the above-describedpackaged beverage. The concentration of non-polymer catechins in thepackaged beverage can be from 0.092 to 0.5 wt % as in theabove-described packaged beverage. Further, the content of epicatechinsand that of gallates can preferably be similar to their contents in theabove-described packaged beverage. In addition, a bitterness suppressor,a sweetener and other ingredients can also be added to the packagedbeverage, and the pH of the packaged beverage can be preferably from 2to 7, more preferably from 3 to 7, even more preferably from 5 to 7, allat 25° C.

Examples Measurement of Catechins

A catechin composition was diluted with distilled water. Subsequent tofiltration through a filter (0.8 μm), the filtrate was subjected tochromatography at a column temperature of 35° C. by a gradient elutionmethod, which used Solution A and Solution B, while employing ahigh-performance liquid chromatograph (model: “SCL-10AVP”) manufacturedby Shimadzu Corporation and fitted with an LC column packed withoctadecyl-introduced silica gel, “L-Column, TM ODS” (4.6 mm indiameter×250 mm in length; product of Chemicals Evaluation and ResearchInstitute, Japan). A 0.1 mol/L solution of acetic acid in distilledwater and a 0.1 mol/L solution of acetic acid in acetonitrile were usedSolution A and Solution B, respectively. The measurement was conductedunder the conditions of 20 μL injected sample quantity and 280 nm UVdetector wavelength.

Measurement of Caffeine

(Analyzer)

A high-performance liquid chromatograph (manufactured by Hitachi, Ltd.)was used.

Plotter: “D-2500”, Detector: “L-4200”, Pump: “L-7100”,

Autosampler: “L-7200”, Column: “Inertsil ODS-2” (2.1 mm innerdiameter×250 mm length).

(Analysis Conditions)

Injected sample quantity: 10 μL

Flow rate: 1.0 mL/min

Detection wavelength of UV spectrophotometer: 280 nm

Eluent A: 0.1 M solution of acetic acid in water

Eluent B: 0.1 M solution of acetic acid in acetonitrile

Concentration gradient conditions (vol. %)

Time Eluent A Eluent B 0 min 97% 3% 5 min 97% 3% 37 min 80% 20%  43 min80% 20%  43.5 min  0% 100%  48.5 min  0% 100%  49 min 97% 3% 62 min 97%3% (Retention time of caffeine) Caffeine: 27.2 min

From each area % determined here, the corresponding wt % was determinedbased on the standard substance.

Measurement of Oxalic Acid

An ion chromatograph (model: “DXAQ 1110”; manufactured by Japan DionexCo., Ltd.) was fitted with columns (“IonPac AS4A-SC”, 4×250 mm column),and was connected to a suppressor, “ASRS-ULTRA” (manufactured by DionexCorporation). Measurement of oxalic acid was performed in the recyclemode. As mobile phases, a 1.8 mmol/L Na₂CO₃ aqueous solution and 1.7mmol/L NaHCO₃ aqueous solution were fed at 1.0 mL/min. The injectedsample quantity was set at 25 μL. An electrical conductivity detectorwas used as a detector.

Measurement of Total Polyphenols

Using ethyl gallate as a standard solution, total polyphenols weredetermined as an amount converted to gallic acid by the ferrous tartratemethod (referential publication: “Green Tea Polyphenols” (in Japanese),Technology Series for the Effective Utilization of FunctionalIngredients for Beverages and Foods, No. 10). A sample (5 mL) wasstained with the standard ferrous tartrate solution (5 mL). With aphosphate buffer, the volume of the thus-stained sample was adjusted to25 mL. Its absorbance was measured at 540 nm, and from a calibrationline for ethyl gallate, the amount of total polyphenols was determined.

Preparation of the standard ferrous tartrate solution: Ferrous sulfateheptahydrate (100 mg) and potassium sodium tartrate (Rochelle salt, 500mg) were dissolved with distilled water to 100 mL.

Preparation of the phosphate buffer: A 1/15 M solution of disodiumhydrogenphosphate and a 1/15 M solution of sodium dihydrogenphosphatewere mixed to give pH 7.5.

Ranking of Hue (Absorbance)

(Analyzer)

An analyzer, “UV MINI1240” (manufactured by Shimadzu Corporation) wasused.

Absorbance values were measured at 450 nm by a spectrophotometer. Ineach measurement, the catechin composition after its purification wasdiluted with deionized water such that the concentration of catechinswas adjusted to 100 mg %. Using a sample of the diluted composition, itsabsorbance was measured, and the absorbance was employed as an index forhue.

Visual Ranking of Stability

Each catechin composition after its purification was diluted withdeionized water such that the concentration of catechins was adjusted to100 mg %. A sample for ranking, which had been placed in a 50-mL vial,was observed for the conditions of its contents on an illuminator tovisually determine its stability.

Example 1 & Comparative Examples 1-2

Under the conditions shown in Table 1, a caffeine-containing catechincomposition was treated to remove caffeine.

It is to be noted that in the employed caffeine-containing catechincomposition (“POLYPHENONE HG”, product of Tokyo Food Techno Co., Ltd.),the content of non-polymer catechins: 33.70 wt %, the content ofcaffeine: 5.5 wt %, non-polymer catechins/caffeine=6.1, and the contentof gallates: 50.7 wt %.

Treatment Processes (1) Example 1

The caffeine-containing catechin composition (“POLYPHENONE HG”, productof Tokyo Food Techno Co., Ltd.; 100 g) was suspended in a 95% aqueoussolution of ethanol (490.9 g) at room temperature under stirring at 250rpm, and subsequent to the addition of activated carbon (“KURARAY COALGLC”, product of Kuraray Chemical K.K.; 20 g), stirring was continuedfor about 10 minutes. After a 40% aqueous solution of ethanol (409.1 g)was added dropwise over 10 minutes, stirring was continued for about 30minutes still at room temperature. The activated carbon and aprecipitate were filtered off through No. 2 filter paper, followed bythe re-filtration through a 0.2-μm membrane filter. Finally, deionizedwater (200 g) was added to the filtrate, and ethanol was distilled offat 40° C. and 25 Torr to afford a product.

(2) Comparative Example 1

Treatment was conducted in a similar manner as in Example 1 except thatthe activated carbon was not added.

(3) Comparative Example 2

The caffeine-containing catechin composition (“POLYPHENONE HG”, productof Tokyo Food Techno Co., Ltd.; 100 g) was suspended in water (900 g) atroom temperature under stirring at 250 rpm, and subsequent to theaddition of activated carbon (“KURARAY COAL GLC”, product of KurarayChemical K.K.; 20 g), stirring was continued for about 20 minutes.Subsequently, stirring was continued for about 30 minutes still at roomtemperature. Subsequent to filtration through No. 2 filter paper,re-filtration was conducted through a 0.2-μm membrane filter. Finally,until the water content was reduced to a similar level as in Example 1,water was caused to gradually evaporate in a drier to afford a product.

TABLE 1 Example Comp. Ex. Comp. Ex. 1 1 2 Caffeine-containing catechincomposition (g) 100 100 100 (“POLYPHENONE HG”, product to Tokyo FoodTechno Co., Ltd) Ethanol (g) 630 630 0 Water (g) 270 270 900 Activatedcarbon (g) (“KURARAY COAL GLC”, 20 0 20 product of Kuraray ChemicalK.K.) Organic solvent/water (weight ratio) 70/30 70/30 0/100 Amounts ofcatechins after removal of ethanol¹⁾ (wt %) GC (gallocatechin) 6.78 6.067.27 EGC (epigallocatechin) 31.6 34.0 34.2 C (catechin) 2.10 1.92 0.98EC (epicatechin) 9.04 9.22 8.77 EGCg (epigallocatechin gallate) 37.736.1 36.4 GCg (gallocatechin gallate) 1.47 0.88 1.50 ECg (epicatechingallate) 10.6 11.0 10.2 Cg (catechin gallate) 0.68 0.88 0.75 Amount ofcatechins after purification/ 1.037 1.057 0.955 amount of catechinsbefore purification Concentration of caffeine after purification²⁾ (mg%) 17.8 30.0 18.6 Amount of caffeine after purification/ 0.591 1.000.955 Amount of caffeine before purification [—] Non-polymer catechinsafter purification/ 10.7 6.4 9.4 caffeine after purification [—] Contentof gallates in non-polymer catechins 50.3 49.1 48.0 after treatment (wt.%) Absorbance(—) 0.052 0.107 0.163 Evaluation of purified product Tastewas good, Caffeine The hue of the and the hue of the was not purifiedproduct purified product removed. was deteriorated was also good.although no problem arose in taste. ²⁾Composition of non-polymercatechins in “POLYPHENONE HG” preparation: GC (gallocatechin): 6.39%,EGC (epigallocatechin): 29.42%, C (catechin): 2.16%, EC (epicatechin):10.3%, EGCg (epigallocatechin gallate): 37.13%, GCg (gallocatechingallate): 1.93%, ECg (epicatechin gallate): 11.89%, Cg (catechingallate): 0.79%; content of gallates: 51.73%, content of gallocatechins:74.88%. ²⁾Amount of caffeine in the aqueous solution of “POLYPHENONE HG”= 30.1 mg/100 g = 30.1 mg % (Concentration of caffeine based on thewater content after purification).

As evident from the results in Table 1, the treatment of acaffeine-containing catechin composition by the present invention makesit possible to selectively remove caffeine while retaining thecomposition of catechins, and to obtain a catechin composition with animproved hue.

Examples 2-3 & Comparative Examples 3-4

Under the conditions shown in Table 2, a caffeine-containing catechincomposition was treated to remove caffeine.

It is to be noted that in the employed caffeine-containing catechincomposition (“POLYPHENONE HG”, product of Tokyo Food Techno Co., Ltd.),the content of non-polymer catechins: 33.70 wt %, the content ofcaffeine: 5.5 wt %, non-polymer catechins/caffeine=6.1, and the contentof gallates: 50.7 wt %.

(Treatment Process of Example 2)

The caffeine-containing catechin composition (“POLYPHENONE HG”, productof Tokyo Food Techno Co., Ltd.; 100 g) was suspended in a 95% aqueoussolution of ethanol (490.9 g) at room temperature under stirring at 250rpm, and subsequent to the addition of activated carbon (“KURARAY COALGLC”, product of Kuraray Chemical K. K.; 20 g) and acid clay (“MIZUKAACE #600”, product of Mizusawa Chemical Industries, Ltd.; 100 g),stirring was continued for about 10 minutes. After a 40% aqueoussolution of ethanol (409.1 g) was added dropwise over 10 minutes,stirring was continued for about 30 minutes still at room temperature.The activated carbon and a precipitate were filtered off through No. 2filter paper, followed by the re-filtration through a 0.2-μm membranefilter. Finally, deionized water (200 g) was added to the filtrate, andethanol was distilled off at 40° C. and 25 Torr to afford a product.

(Treatment Process of Example 3)

The caffeine-containing catechin composition (“POLYPHENONE HG”, productof Tokyo Food Techno Co., Ltd.; 300 g) was suspended in a 47.5% aqueoussolution of ethanol (630 g) at room temperature under stirring at 250rpm, and subsequent to dissolution for 20 minutes, a 95% aqueoussolution of ethanol (570 g) was added dropwise over 20 minutes. Afteracid clay (“MIZUKA ACE #600”, product of Mizusawa Chemical Industries,Ltd.; 30 g) was added, stirring was continued for 2 hours. The activatedcarbon and a precipitate were then filtered off through No. 2 filterpaper. Activated carbon (“KURARAY COAL GLC”, product of Kuraray ChemicalK.K.; 30 g) was then added to the filtrate, followed by stirring for 2hours. Subsequently, the activated carbon was filtered off through No. 2filter paper, and re-filtration was conducted through a 0.2-μm membranefilter. Finally, deionized water (230 g) was added to the filtrate, andethanol was distilled off at 40° C. and 25 Torr to afford a product.

(Treatment Process of Comparative Example 3)

The caffeine-containing catechin composition (“POLYPHENONE HG”, productof Tokyo Food Techno Co., Ltd.; 100 g) was suspended in water (900 g) atroom temperature under stirring at 250 rpm, and subsequent to theaddition of acid clay (“MIZUKA ACE #600”, product of Mizusawa ChemicalIndustries, Ltd.; 100 g), stirring was continued for about 20 minutes.Subsequently, stirring was continued for about 30 minutes still at roomtemperature. Subsequent to filtration through No. 2 filter paper,re-filtration was conducted through a 0.2-μm membrane filter. Finally,until the water content was reduced to a similar level as in Example 2,water was gradually evaporated in a drier to of ford a product.

(Treatment Process of Comparative Example 4)

The caffeine-containing catechin composition (“POLYPHENONE HG”, productof Tokyo Food Techno Co., Ltd.; 100 g) was suspended in water (900 g) atroom temperature under stirring at 250 rpm, and subsequent to theaddition of activated carbon (“KURARAY COAL GLC”, product of KurarayChemical K.K.; 20 g) and acid clay (“MIZUKA ACE #600”, product ofMizusawa Chemical Industries, Ltd.; 100 g), stirring was continued forabout 20 minutes. Subsequently, stirring was continued for about 30minutes still at room temperature. Subsequent to filtration through No.2 filter paper, re-filtration was conducted through a 0.2-μm membranefilter. Finally, until the water content was reduced to a similar levelas in Example 2, water was gradually evaporated in a drier to afford aproduct.

TABLE 2 Example Example Comp. Ex. Comp. Ex. 2 3 3 4 Caffeine-containingcatechin composition (g) 100 300 100 100 (“POLYPHENONE HG”, product toTokyo Food Techno Co., Ltd) Ethanol (g) 630 825.8 0 0 Water (g) 270374.2 900 900 Activated carbon (g) (“KURARAY COAL GLC”, 20 30 0 20product of Kuraray Chemical K.K.) Acid clay (g) (“MIZUKA ACE #600”, 10030 100 100 product of Mizusawa Chemical Industries, Ltd.) Organicsolvent/water (weight ratio) 70/30 71/29 0/100 0/100 Amounts ofnon-polymer catechins after treatment (wt %)¹⁾ GC (gallocatechin) 6.817.21 6.75 7.42 EGC (epigallocatechin) 32.08 29.74 31.75 34.72 C(catechin) 2.09 1.36 0.22 2.02 EC (epicatechin) 8.96 9.38 9.64 8.24 EGCg(epigallocatechin gallate) 37.12 37.76 35.93 35.86 GCg (gallocatechingallate) 1.39 1.80 1.39 1.47 ECg (epicatechin gallate) 10.78 11.31 11.349.61 Cg (catechin gallate) 0.75 0.45 0.94 0.66 Non-polymercatechins/caffeine after treatment 38.8 8.8 23.6 42.6 (weight ratio)Amount of caffeine after treatment²⁾ (mg/100 mL) 4.8 18.1 8.2 4.3Content of gallates in non-polymer catechins 50.0 51.3 49.6 47.6 aftertreatment (wt %) Content of gallocatechins in non-polymer catechins 77.476.5 75.8 79.5 after treatment (wt %) Absorbance(—) 0.044 0.073 0.5350.270 Evaluation of purified product Caffeine was Caffeine was Hue wasHue was decreased, and hue decreased, and hue deteriorated, anddeteriorated, and and stability were and stability were a precipitate aprecipitate both good. both good. occurred occurred ¹⁾Composition ofnon-polymer catechins in “POLYPHENONE HG” preparation: GC(gallocatechin): 6.39%, EGC (epigallocatechin): 29.42%, C (catechin):2.16%, EC (epicatechin): 10.3%, EGCg (epigallocatechin gallate): 37.13%,GCg (gallocatechin gallate): 1.93%, ECg (epicatechin gallate): 11.89%,Cg (catechin gallate): 0.79%; content of gallates: 51.73%, content ofgallocatechins: 74.88%. ²⁾Amount of caffeine when “POLYPHENONE HG” wasdissolved in water: 30.1 mg/100 g.

As evident from the results in Table 2, the treatment of acaffeine-containing catechin composition by the present invention makesit possible to selectively remove caffeine while retaining thecomposition of catechins, and to obtain a catechin composition with animproved hue.

Example 4

The caffeine-containing catechin composition (“POLYPHENONE HG”, productof Tokyo Food Techno Co., Ltd.; the content of non-polymer catechins:33.70 wt %, the content of caffeine: 5.5 wt %, non-polymercatechins/caffeine: 6.1, the content of gallates: 50.7 wt %; 12.8 kg)was dissolved in deionized water (13.44 kg). 95% ethanol (13.44 kg) wasthen added, followed by mixing and stirring. Similarly, 95% ethanol wasthen added at a dropping rate of 22 kg/hr to conduct extraction.Subsequent to the extraction for 30 minutes, acid clay (2 kg) was addedto the resultant extract (64 kg) to conduct a clay treatment. After theclay treatment, solid-liquid separation was conducted by filtration. Tothe clay-treated filtrate obtained as described above, activated carbon(1 kg) was added to conduct an activated carbon treatment. After theactivated carbon treatment, filtration was applied to collect afiltrate. The thus-obtained filtrate was concentrated to remove ethanol,and the solid concentration was adjusted with deionized water to afforda desired product.

TABLE 3 Analysis Data of Caffeine-containing Tea Extract Content ofgallates in non-polymer catechins wt % 53.68 Non-polymercatechins/caffeine — 10.31 Non-polymer catechins/(sucrose + glucose) —4.76 Dietary fibers in product in terms of solid content wt % 0.50Absorbance — 0.082 * The data of sucrose, glucose (the HPLC method) anddietary fibers (the enzymatic gravimetric method) are the analysis datadisclosed by Japan Food Research Laboratories (described in the May 2000edition of “Table of Fees on Primary Items for Analysis” (in Japanese),Japan Food Research Laboratories).

Examples 5-7

Using the purified products of the green tea extract as obtained inExamples 1 to 3, the packaged beverages shown in Table 4 were produced.

TABLE 4 Examples 5 6 7 Purified product¹⁾ of green tea extract (g) 5.25Purified product²⁾ of green tea extract (g) 5.36 Purified product³⁾ ofgreen tea extract (g) 6.27 β-cyclodextrin (g) 2.8 2.8 2.8 Sodiumascorbate (g) 1.0 1.0 1.0 Sodium bicarbonate (g) q.s. q.s. q.s.Commercially-available drinking water⁴⁾ (g) Balance Balance BalanceTotal weight (g) 1,000 1,000 1,000 pH 6.2 6.2 6.2 Post-treatmenttemperature (° C.) 139 139 139 Post-treatment time (min) 8 8 8 Totalamount of non-polymer catechins in beverage wt % 0.1 0.1 0.1 Amount ofcaffeine in beverage wt % 0.0093 0.0026 0.012 Content of gallates innon-polymer catechins in beverage wt % 50.3 50.0 51.3 Non-polymercatechins/caffeine in beverage [—] 10.7 38.8 8.8 Color tone stability ofbeverage⁵⁾ Good Very good Good ¹⁾Purified product of green tea extractas obtained in Example 1. ²⁾Purified product of green tea extract asobtained in Example 2. ³⁾Purified product of green tea extract asobtained in Example 3. ⁴⁾Commercially-available drinking water. Qualitymarking - calcium content: 7.1 mg/100 mL, magnesium content: 2.4 mg/100mL, sodium content: 4.7 mg/100 mL. ⁵⁾Each packaged beverage which hadbeen subjected to a post-treatment was left over at 55° C. for 1 week,during which the packaged beverage was observed for any change inappearance.

Examples 8-11 & Comparative Examples 5-6

Purification of the commercially-available catechin preparation wasconducted by solid-liquid extraction under varied organic solvent/waterratios as shown in Table 5. Specifically, ethanol or acetone was used asan organic solvent, and the catechin preparation was added to a mixedsolvent of the organic solvent and water. After water was added to givethe corresponding organic solvent/water ratio shown in Table 5, theresulting mixture was stirred and then filtered to remove solids.Further, the organic solvent was distilled off under reduced pressure.

TABLE 5 Example Example Example Example Comp. Ex. Comp. Ex. 8 9 10 11 56 Amount of “POLYPHENONE HG”²⁾ to be suspended g 10 10 10 10 10 10Amount of ethanol upon suspension g 100 80 95 60 100 Amount of acetoneupon suspension g 100 Amount of water upon suspension g 20 5 40 Totalamount upon suspension g 110 110 110 110 110 110 Amount of water addedfor solid-liquid extraction g 42.9 42.9 60 5.6 20 150 Organicsolvent/water ratio upon solid-liquid — 70/30 70/30 50/50 90/10 50/5040/60 extraction Oxalic acid/non-polymer catechins ratio after — 0.0110.005 0.031 0.007 0.037 0.060 purification Concentration of non-polymercatechins in solids wt % 37 37 34 42 34 — after purification Content ofgallates in non-polymer catechins wt % 55.36 54.71 55.64 53.77 51.17 —contained in solids after purification Evaluation of flavor and taste of0.1 wt % dissolution No No Slight No Acid Acid system of non-polymercatechins problem problem acid problem taste was taste was taste felt.strong. was felt. 1) Each catechin preparation after its purificationwas added to deionized water such that the concentration of non-polymercatechins was adjusted to 0.1 wt %. Evaluation was performed by threetaste panelists. ²⁾Concentrate of a green tea extract “POLYPHENONE HG”(product of Tokyo Food Techno Co., Ltd.) The content of non-polymercatechins: 33.70 wt %, the content of oxalic acid: 2.03 wt %, oxalicacid/non-polymer catechins: 0.060

It has been found that by adjusting the ratio of oxalic acid tonon-polymer catechins to 0.01 or so as a result of purification, theeffects of taste components existing in a catechin preparation become nolonger sensible to give good results from the standpoint of flavor andtaste. It has also been found that, when the ratio of an organic solventto water is set at 5/5 upon conducting solid-liquid extraction, adifference arises in the taste of a purified product depending upon theratio of an organic solvent to water upon suspension.

Examples 12-15 & Comparative Example 7

By changing the ratio of an organic solvent to water upon liquid-liquidextraction as shown in Table 6 to adjust the amount of insolublecomponents to be formed, purification of the commercially-availablecatechin preparation was conducted. Specifically, thecommercially-available catechin preparation was dissolved in a mixedsolvent of water and ethanol, and then, ethanol was added to adjust theethanol/water ratio to the corresponding ratio described in Table 1 suchthat a precipitate was caused to occur. Solids were filtered off, andthen, ethanol was distilled off under reduced pressure.

TABLE 6 Example Example Example Example Comp. Ex. 12 13 14 15 7 Amountof “POLYPHENONE HG”²⁾ to be dissolved g 10 10 10 10 10 Amount of ethanolupon dissolution g 60 40 30 50 0 Amount of water upon dissolution g 4060 70 50 100 Total amount upon dissolution g 100 100 100 100 100 Amountof ethanol added for liquid-liquid extraction g 33.3 100 133.3 150.0233.3 Organic solvent/water ratio upon liquid-liquid — 70/30 70/30 70/3080/20 70/30 extraction Oxalic acid/non-polymer catechins ratio after —0.0016 0.0022 0.0025 0.0014 0.0377 purification Concentration ofnon-polymer catechins in solids wt % 37 37 37 39 37 after purificationContent of gallates in non-polymer catechins wt % 56.77 56.65 56.1456.80 56.26 contained in solids after purification Evaluation of flavorand taste of 0.1 wt % dissolution No No No No Acid taste system ofnon-polymer catechins problem problem problem problem was felt. 1) Eachcatechin preparation after its purification was added to deionized watersuch that the concentration of non-polymer catechins was adjusted to 0.1wt %. Evaluation was performed by three taste panelists. ²⁾Concentrateof a green tea extract “POLYPHENONE HG” (product of Tokyo Food TechnoCo., Ltd.) The content of non-polymer catechins: 33.70 wt %, the contentof oxalic acid: 2.03 wt %, oxalic acid/non-polymer catechins: 0.060

It has been found that by setting the ethanol/water ratio at 70/30 uponliquid-liquid extraction, the ratio of oxalic acid to non-polymercatechins becomes extremely low after purification and the acid taste ofconventional catechins becomes no longer sensible. It has also beenfound that the efficiency of purification becomes higher by dissolving acatechin preparation in an aqueous ethanol solution rather than in 100%water upon dissolution of the catechin preparation.

Examples 16-17 & Comparative Example 8-9

Packaged beverages were each produced by mixing its correspondingingredients and conducting its corresponding post-treatment as shown inTable 7.

TABLE 7 Examples Comparative Examples 16 17 8 9 Green tea extract¹⁾ (g)3.13 Green tea extract²⁾ (g) 3.10 Concentrate³⁾ of green tea extract (g)0.5 3.5 Ratio of non-polymer catechins to total (—) 0.85 0.91 0.81 0.81polyphenols in the preparation (note) Dried product⁴⁾ of green teaextract (g) 1.0 1.0 1.0 1.0 β-Cyclodextrin (g) 2.8 2.8 2.8 2.8 Sodiumascorbate (g) 1.0 1.0 1.0 1.0 Sodium bicarbonate (g) q.s. q.s. q.s. q.s.Commercially-available drinking water⁵⁾ (g) Balance Balance BalanceBalance Total weight (g) 1,000 1,000 1,000 1,000 pH 6.2 6.2 6.2 6.2Post-treatment temperature (° C.) 139 139 139 139 Post-treatment time(min) 8 8 8 8 Total amount of non-polymer catechins in wt % 0.152 0.1480.05 0.151 beverage Total amount of total polyphenols in wt % 0.1890.167 0.062 0.187 beverage Color tone stability⁶⁾ of beverage Good GoodGood Darkened ¹⁾Green tea extract “POLYPHENONE HG” (product of TokyoFood Techno Co., Ltd.; 100 g) was dispersed in 38 wt % ethanol (420 g).A 92.5% aqueous ethanol solution (540 g) was added dropwise over 10minutes. The resulting mixture was then subjected to aging understirring for 30 minutes. Subsequent to the aging, coarse filtration wasconducted with No. 2 filter paper. The filtrate was then filtered withfilter paper having a 0.2 μm mesh to remove remaining insolublecomponents. To the resulting filtrate, water (200 mL) was added.Subsequent to concentration under reduced pressure, the concentrate wassubjected to lyophilization. The resultant green tea extract - thecontent of non-polymer catechins: 38 wt %, the content of totalpolyphenols: 44.7 wt %, non-polymer catechins/total polyphenols: 0.85.²⁾Green tea extract “POLYPHENONE HG” (product of Tokyo Food Techno Co.,Ltd.; 100 g) was dispersed in 99.5 wt % ethanol (630 g). Water (270 g)was added dropwise over 10 minutes. The resulting mixture was thensubjected to aging under stirring for 30 minutes. Subsequent to theaging, coarse filtration was conducted with No. 2 filter paper. Thefiltrate was then filtered with filter paper having a 0.2 μm mesh toremove remaining insoluble components. To the resulting filtrate, water(200 mL) was added. Subsequent to concentration under reduced pressure,the concentrate was subjected to lyophilization. The resultant green teaextract - the content of non-polymer catechins: 37 wt %, the content oftotal polyphenols: 40.6 wt %, non-polymer catechins/total polyphenols:0.91. ³⁾Green tea extract “POLYPHENONE HG” (product of Tokyo Food TechnoCo., Ltd.). The content of non-polymer catechins: 33.70 wt %, thecontent of total polyphenols: 41.6 wt %, non-polymer catechins/totalpolyphenols: 0.81. ⁴⁾Lyophilized product of green tea extract Sencha(middle-grade green tea) leaves (40 g) were added to hot water (1,000 g)which had been heated to 90° C. With gentle stirring, extraction wasconducted for 5 minutes. Subsequent to the extraction, filtration wasconducted with double No. 2 filter paper, and the filtrate was promptlycooled to room temperature. The extract was lyophilized. The resultantlyophilization product of the green tea extract - the content ofnon-polymer catechins: 33 wt %, the content of total polyphenols: 41 wt%. ⁵⁾Commercially-available drinking water. Quality marking - calciumcontent: 7.1 mg/100 mL, magnesium content: 2.4 mg/100 mL, sodiumcontent: 4.7 mg/100 mL. ⁶⁾Each packaged beverage which had beensubjected to the post-treatment was left over at 55° C. for 1 week,during which the packaged beverage was observed for any change inappearance. As a result of the 55° C. storage test of the packagedbeverages, it turned out that despite the addition of non-polymercatechins at high concentration, the beverages of Examples 16-17remained unchanged in color tone after the storage and were stable. InComparative Example 8, on the other hand, no particular problem arosebecause the content of non-polymer catechins was low. In ComparativeExample 9, however, the beverage had a darker appearance with time.

What we claim is:
 1. A green tea extract, wherein a content weight ratio[(A)/(B)] of (A) non-polymer catechins to (B) total polyphenols is from0.83 to 0.96, and wherein a concentration of non-polymer catechins isfrom 35 to 55 wt %.
 2. The green tea extract of claim 1, wherein: (a) acontent of gallates in non-polymer catechins is from 45 to 60 wt %, (b)a weight ratio of said non-polymer catechins to caffeine is from 8 to40, (c) a weight ratio of said non-polymer catechins to(sucrose+glucose) is from 2 to 15, and (d) dietary fibers amount to 0.5wt % or less of a solid content.
 3. The green tea extract of claim 1,wherein a content of gallates in the non-polymer catechins is from 45 to60 wt %.
 4. The green tea extract of claim 1, wherein a weight ratio ofsaid non-polymer catechins to caffeine is from 8 to
 40. 5. The green teaextract of claim 1, wherein a weight ratio of said non-polymer catechinsto (sucrose+glucose) is from 2 to
 15. 6. The green tea extract of claim1, wherein dietary fibers, if present, amount to 0.5 wt % or less of asolid content.
 7. A packed beverage, comprising a container and thegreen tea extract of claim
 1. 8. The green tea extract of claim 1,comprising gallates and nongallates, wherein a content of the gallatesis greater than a content of the nongallates.